Field of the Invention
The invention relates to an electric tool.
Related Art
An electric tool such as impact driver is provided with a cooling fan. The cooling fan generates cooling wind for cooling a motor and a control substrate. The external air is sucked from an intake hole formed at a housing and the motor and the control substrate are cooled by the air. Then, the air that has been used for the cooling is exhausted from an exhaust hole formed at the housing.
In an electric tool of Patent Document 1 (JP-A-2011-142801), since a cylindrical output part having a motor and a cooling fan arranged thereto communicates with a lower part of the housing, the air is sucked from a place other than the intake hole when the cooling fan is operated. For example, the air may be sucked from a gap between a trigger switch and the housing.
When the air is sucked from a place other than the intake hole, the cooling efficiency is lowered and dust is accumulated at the outside of a circulation route of the cooling wind.
According to the electric tool of Patent Document 1, the cooling fan and the motor control substrate are arranged on the same axis as the motor and the motor control substrate and the motor are cooled by the cooling wind that is generated by the cooling fan.
When the motor control substrate is arranged on the same axis as the motor, the motor control substrate can be efficiently cooled. However, the tool becomes larger in an axial direction of the motor, so that it is difficult to shorten an overall length of the tool.